中文摘要：

提出一种利用待测印鉴（SS）与预留印鉴（MS）之间边缘差异的几何特征判别SS真伪的新方法。利用SIFT（scaleinvariant feature transform）特征配准MS和SS的边缘。刻意伪造的假SS与MS的差异很小，而真印章盖出的不同印鉴也存在微小差异。提出利用不重合的两对应边缘之间的距离和它们的长度判断边缘差异是否由假SS引起。为了便于量化SS与MS边缘的几何差异，定义左差图像LD和右差图像RD。根据Z由和尼，中连通域的位置、长度以及每个连通域中各点的统计特性，计算SS与MS边缘的几何差异大小，将SS判别为真、假或可疑印鉴。对800幅印鉴图像（真、假各400）进行实验。所有假印鉴都被正确识别，6幅真印鉴被识别为可疑印鉴，正确识别率为99．25％

英文摘要：

An automatic seal identification algorithm using geometrical characteristics of edge differences was proposed. Model seal （MS） and sample seal （SS） are registered by matching their SIFT features. The edge difference between MS and a deliberately fake SS is slight, while that between MS and a genuine SS is also small due to the variety of imprinting conditions. To quantify the edge difference, a left difference Lo and a right difference Ro are defined. The connected components in Lo and RD are considered as pieces of non-overlapped edges. The area of each connected component is computed as the length parameter, and the average distance of pixels in each connected component to their corresponding pixels is taken as the distance parameter. According to these two parameters, an SS is classified as true, false or doubtful. 800 sample seals were tested, in which 400 are genuine and 400 are fake. The fake seals are almost identical to their model seals, but none of them was mis-classified. 6 genuine seals that have serious distortions were wrongly regarded as doubtful. The identification precision is 99.25%.